Petzl Bongo Hammer One Size. Specifications for Petzl Bongo Hammer: Manufacturer: Petzl Length: 33 cm Weight: 680 g Application: Climbing Features of Petzl Bongo Hammer Rubber grip reduces vibrations Hole in shaft for attaching a keeper cord Hole in head for attaching a piton removal device Curved head to facilitate piton removal Package Contents: Petzl Bongo Hammer Petzl P27: Bongo Hammer One Size